WHEN YOU FIRST TURN that dial to “M,” it can be thrilling and unnecessarily terrifying. Shooting in Manual isn’t some special club you have to be a “pro” to join — it takes a basic understanding of the exposure triangle, depth of field, and your light meter. Yes, there’s a learning curve. Yes, there are many times where switching to Aperture Priority or Shutter Priority might be a good move. And yes, you will ruin a lot of photos along the way.
Racing towards Manual before you’re ready will likely result in a lot of frustration. Mastering Exposure Locking (which is used in Av/A and Tv/S), for example, will build a great foundation for taking total control in Manual.
The biggest change that occurs when you switch to Manual is that you must select all three settings of the Exposure Triangle: aperture, shutter speed, and ISO. Before, in Aperture or Shutter Priority, you only selected two, and allowed the camera to calculate the third. The camera often gets confused, though in semi-automatic modes it can be adjusted using Exposure Locking. In Manual, however, the Exposure Lock Button won’t work.
So how do you know which settings to choose? It’s a valid question. In Manual, you have to use your Exposure Meter as a guide to select all three. When the meter is at or near 0, your exposure is “correct.” I put “correct” in quotes, because as you gain confidence in this area there are many creative exposures to try out — which will throw off your meter but result in a great shot. But first, we need to master a basic, correct exposure.
So back to that pesky question: Which settings should I choose? I’ve broken this into four steps which should lead you to your answer.
1. Choose / check your metering mode.
By default, cameras are set to “Evaluative.” Most pros prefer Spot or Partial Metering, while others swear by Centre-Weighted. You can read all about them in this article. It will effect how you get your exposure reading later on. Choose the mode you’re most comfortable with.
2. Start with your priority.
If the priority is a particular aperture (say, wide for a portrait, or narrow for a landscape), then set that first. You do need to have a good grasp of Depth of Field — isolation vs storytelling vs sweet-spot. This is laid out in our beginner’s guide to understanding aperture priority, if you need a refresher.
If your priority is time — to either freeze action or imply motion (as covered in when to use shutter priority and why) — then set the time value that you want. If you are implying motion, break out the tripod.
3. Make metering and second setting adjustments.
Once you’ve selected your main priority, use your light meter to take a reading. You want to take a reading off of your subject, or the brightest part of the image, or whatever part of the image you want most accurately exposed. Then adjust the 2nd setting until your light meter is at 0.
For example, if you’ve selected f/3.5 for a portrait, and your Exposure Meter reads under-exposed (not enough light), you’ll need to lower the shutter speed (letting in more light) until the meter reaches 0. Alternatively, if it’s over-exposed (too much light), you’ll need to increase shutter speed (shutting out more light) to reach 0. On Canon, over-exposed is to the right, and under-exposed is to the left. It’s the opposite on Nikon.
The same goes for shutter speed. In order to reach 0, and depending on how bright or dark your scene is, you’ll need to open or close the aperture. Always bear your priority in mind.
Tip: If you’re freezing action, even though your priority is shutter speed, you still want to think about aperture. A wide aperture allows for the fastest possible shutter speed. So if you set your shutter speed to 1/500, and to reach 0 on your meter you get f/9, you might as well open up your aperture further. This increases the amount of light entering drastically, allowing you to increase your shutter speed to compensate. This isn’t always the case — there may be times you want f/9 for sharpness and depth of field — but for the most part it’s a rule that works well.
4. Do you require ISO?
Hopefully you keep your ISO set to 100 or 200 as a default (as opposed to Auto). Auto can be useful in some circumstances, but in Manual it’s best to keep control over all your settings. We want our ISO as low as possible because it reduces noise in the image, but Auto ISO can also mess with your other settings (increasing at least one of them to compensate for the extra sensitivity).
However, if you reach 0 on your meter, and your shutter speed is not fast enough (if you’re freezing action, or shooting handheld), first make sure your aperture is wide open. If it is, then you can boost your ISO until you are able to reach the shutter speed you need.
Modern DSLRs go up to 6400, while professional-grade cameras hit 12000, 25000, or even over 100,000 (yikes). So if you reach 0 on your exposure meter, but to do so your shutter speed has dipped too low, boost your ISO, which will allow you to increase your shutter speed.
If you’re at a high ISO and your shutter speed is still too short, and your aperture is wide open, you need to either attach a flash, or admit that the scene is too dark for a sharp capture. Consider long exposure (if you have a tripod), or just enjoy the moment.
Tip: For long exposures, use your two-second timer (10 seconds on some cameras), so that you don’t shake the camera as you release the shutter (or use a wireless trigger).
In the image to the right, I knew my priority was aperture, because it was such a tight portrait of this older, smoking, Cambodian man. I set my aperture to f/2.8 — the widest my lens could go — and took a meter reading to the left side of his face. I did this because he was being side-lit; it was mid-afternoon and the light was bouncing brightly off the Tonle Sap River. I reached 0 when my shutter speed was 1/250. That was fast enough, so I didn’t have to touch my ISO. I got my focus on his eyes and fired away.
In this next image below, I knew I wanted to get some traffic streaks to depict the chaos of downtown Buenos Aires, so that was my priority. I set my shutter speed to 2” (two full seconds) — but that’s letting in a lot of light. To compensate, I increased my aperture to f/13. It was pouring rain, and not too bright, and this combination did the trick. My ISO stayed at 100 because I was trying to cut out light, not add any extra. I metered off of my subject, and put my focal point on the “Havanna” sign.
Lastly, below is an image where I did need to use my ISO. We were in Cambodia shooting a religious ceremony that takes place before dawn — it was pitch black except for candles. My camera was maxed out at f/2.8, but to reach a decent exposure, my shutter speed was too slow to freeze a face. So, I boosted my ISO to 3600, allowing me to get to 1/20th. 1/20th is still not much, but because I was using a tripod it did the trick. I metered off (and focused on) the woman’s face to get detail there, even though it blew out the whites in the candle.